Summary:
MyRocks testing found an issue that while iterating over keys
that are outside the prefix, sometimes wrong results were seen for keys
outside the prefix. We now tighten the range of keys seen with a new
read option called prefix_seen_at_start. This remembers the starting
prefix and then compares it on a Next for equality of prefix. If they
are from a different prefix, it sets valid to false.

Test Plan: PrefixTest.PrefixValid

Reviewers: IslamAbdelRahman, sdong, yhchiang, anthony

Reviewed By: anthony

Subscribers: spetrunia, hermanlee4, yoshinorim, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50211

Summary: As title. Let's run it for 1 hour.

Test Plan: How can I test legocastle changes?

Reviewers: IslamAbdelRahman, yhchiang, rven, sdong, anthony, kradhakrishnan

Reviewed By: kradhakrishnan

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49653

Summary:
Move some of the items in public API changes section to to new
features section.

Test Plan: no code change.

Reviewers: igor, sdong, anthony, IslamAbdelRahman

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50229

Summary: Fix build for clang

Test Plan:
USE_CLANG=1 make all -j64
make clean
make check -j64

Reviewers: yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D50217

Fix appveyor build failure

Summary:
This patch introduces OptionsSanityCheckLevel internally to enable
sanity check rocksdb options.

Utilities API will be added in the follow-up diffs.

Test Plan: Added more tests in options_test

Reviewers: igor, IslamAbdelRahman, sdong, anthony

Reviewed By: anthony

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49515

Summary:
Fixed the following compile error in RocksDBLite:

18:00:33   CC       utilities/memory/memory_test.o
18:00:33 utilities/memory/memory_test.cc: In function ‘int main(int, char**)’:
18:00:33 utilities/memory/memory_test.cc:268:66: error: ‘printf’ was not declared in this scope
18:00:33    printf("Skipped in RocksDBLite as utilities are not supported.");
18:00:33                                                                   ^

Test Plan: make OPT=-DROCKSDB_LITE memory_test

Reviewers: igor, sdong, anthony, IslamAbdelRahman

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D50145

Summary:
This patch introduces utilities/memory, which currently includes
GetApproximateMemoryUsageByType that reports different types of
rocksdb memory usage given a list of input DBs.

The API also take care of the case where Cache could be shared
across multiple column families / multiple db instances.

Currently, it reports memory usage of memtable, table-readers
and cache.

Test Plan: utilities/memory/memory_test.cc

Reviewers: igor, anthony, IslamAbdelRahman, sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49257

Summary:
This patch adds GetAggregatedIntProperty() that returns the aggregated
value from all CFs

Test Plan: Added a test in db_test

Reviewers: igor, sdong, anthony, IslamAbdelRahman, rven

Reviewed By: rven

Subscribers: rven, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49497

Summary:
This diff is a first step towards an iterator based interface for the
SearchRadial method which replaces a vector of GeoObjects with an
iterator for GeoObjects. This diff works by just wrapping the iterator
for the encapsulated vector of GeoObjects. A future diff could extend
this approach by defining an interator in terms of the underlying
iteration in SearchRadial which would then remove the need to have
an in-memory representation for all the matching GeoObjects.
Fixes T8421387

Test Plan:
The existing tests have been modified to work with the new
interface.

Reviewers: IslamAbdelRahman, kradhakrishnan, dhruba, igor

Reviewed By: igor

Subscribers: igor, dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D50031

Add Option to Skip Flushing in TableBuilder

Enable compiler warnings

  C4101 'identifier' : unreferenced local variable
  C4189 'identifier' : local variable is initialized but not referenced
  C4100 'identifier' : unreferenced formal parameter
  C4296 'operator' : expression is always false

Fix introduced in 2ab7065a was reverted by 18285c1e.

Corrects:

db/memtablerep_bench.cc:135:22: error: ‘FLAGS_env’ defined but not used [-Werror=unused-variable]
 static rocksdb::Env* FLAGS_env = rocksdb::Env::Default();
                      ^
cc1plus: all warnings being treated as errors
Makefile:1147: recipe for target 'db/memtablerep_bench.o' failed

Do not suppress C4018 'expression' : signed/unsigned mismatch

  The code compiles cleanly for the most part. Fix db_test.
  Move debug file to testutil library.

Summary:
Update DB::AddFile() restrictions to be
  - Key range in loaded table file don't overlap with existing keys or tombstones in DB.
  - No other writes happen during AddFile call.

The updated AddFile() will verify that the file key range don't overlap with any keys or tombstones in the DB, and then add the file to L0

Test Plan: unit tests

Reviewers: igor, rven, anthony, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: adsharma, ameyag, dhruba

Differential Revision: https://reviews.facebook.net/D49233

Summary: Currently db_bnech's --compaction_pri default is set to be rocksdb::Options().compaction_style. Change it to rocksdb::Options().compaction_pri. Although, for now both is 0.

Test Plan: Build db_bench

Reviewers: anthony, rven, IslamAbdelRahman, kradhakrishnan, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D49773

Summary: new_cf_opt.table_factory->Name() is char*, ASSERT_EQ doesn't work with char* directly. Construct a string using it.

Test Plan: Run the test that failed.

Reviewers: igor, kradhakrishnan, rven, IslamAbdelRahman, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D49767

Support PlainTableOption in option_helper.cc

Summary:
CreateLoggerFromOptions have some parameters like  db_log_dir and env, these parameters are redundant since they already exist in DBOptions

this patch remove the redundant parameters and expose CreateLoggerFromOptions to users

Test Plan: make check

Reviewers: igor, anthony, yhchiang, rven, kradhakrishnan, sdong

Reviewed By: sdong

Subscribers: dhruba, hermanlee4

Differential Revision: https://reviews.facebook.net/D49713

Summary: Run "make format" for some recent commits.

Test Plan: Build and run tests

Reviewers: IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D49707

Implement smart buffer management in Windows Env.

Fix compilation problem on Windows.

  char is not a valid template parameter for std::uniform_int_distribution
  according to the standard. Replacing with int should be just fine.

Summary: We don't have access to GetLiveFilesMetadata() in RocksDB lite. If compiling write_stress for lite, I skip the check for leaked files, which depends on this function.

Test Plan: OPT=-DROCKSDB_LITE m write_stress

Reviewers: sdong

Reviewed By: sdong

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D49647

Summary:
An uninitialized parameter was being passed into the call to fetch the table
properties during the compaction notification callbacks.

Test Plan:
Build it with myrocks and verify unit test passed.
Run unit tests.

Reviewers: rven, yhchiang, igor

Reviewed By: igor

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D49635

Summary:
The goal of this diff is to create a simple stress test with focus on catching:
* bugs in compaction/flush processes, especially the ones that cause assertion errors
* bugs in the code that deletes obsolete files

There are two parts of the test:
* write_stress, a binary that writes to the database
* write_stress_runner.py, a script that invokes and kills write_stress

Here are some interesting parts of write_stress:
* Runs with very high concurrency of compactions and flushes (32 threads total) and tries to create a huge amount of small files
* The keys written to the database are not uniformly distributed -- there is a 3-character prefix that mutates occasionally (in prefix mutator thread), in such a way that the first character mutates slower than second, which mutates slower than third character. That way, the compaction stress tests some interesting compaction features like trivial moves and bottommost level calculation
* There is a thread that creates an iterator, holds it for couple of seconds and then iterates over all keys. This is supposed to test RocksDB's abilities to keep the files alive when there are references to them.
* Some writes trigger WAL sync. This is stress testing our WAL sync code.
* At the end of the run, we make sure that we didn't leak any of the sst files

write_stress_runner.py changes the mode in which we run write_stress and also kills and restarts it. There are some interesting characteristics:
* At the beginning we divide the full test runtime into smaller parts -- shorter runtimes (couple of seconds) and longer runtimes (100, 1000) seconds
* The first time we run write_stress, we destroy the old DB. Every next time during the test, we use the same DB.
* We can run in kill mode or clean-restart mode. Kill mode kills the write_stress violently.
* We can run in mode where delete_obsolete_files_with_fullscan is true or false
* We can run with low_open_files mode turned on or off. When it's turned on, we configure table cache to only hold a couple of files -- that way we need to reopen files every time we access them.

Another goal was to create a stress test without a lot of parameters. So tools/write_stress_runner.py should only take one parameter -- runtime_sec and it should figure out everything else on its own.

In a separate diff, I'll add this new test to our nightly legocastle runs.

Test Plan:
The goal of this test was to retroactively catch the following bugs: D33045, D48201, D46899, D42399. I failed to reproduce D48201, but all others have been caught!

When i reverted https://reviews.facebook.net/D33045:

     ./write_stress --runtime_sec=200 --low_open_files_mode=true
     Iterator statuts not OK: IO error: /fast-rocksdb-tmp/rocksdb_test/write_stress/089166.sst: No such file or directory

When i reverted https://reviews.facebook.net/D42399:

    python tools/write_stress_runner.py --runtime_sec=5000
    Running write_stress, will kill after 5 seconds: ./write_stress --runtime_sec=-1
    Running write_stress, will kill after 2 seconds: ./write_stress --runtime_sec=-1 --destroy_db=false --delete_obsolete_files_with_fullscan=true
    Running write_stress, will kill after 7 seconds: ./write_stress --runtime_sec=-1 --destroy_db=false
    Running write_stress, will kill after 5 seconds: ./write_stress --runtime_sec=-1 --destroy_db=false
    Running write_stress, will kill after 8 seconds: ./write_stress --runtime_sec=-1 --destroy_db=false --low_open_files_mode=true
    Write to DB failed: IO error: /fast-rocksdb-tmp/rocksdb_test/write_stress/019250.sst: No such file or directory
    ERROR: write_stress died with exitcode=-6

When i reverted https://reviews.facebook.net/D46899:

    python tools/write_stress_runner.py --runtime_sec=1000
    runtime: 1000
    Going to execute write stress for [3, 3, 100, 3, 2, 100, 1, 788]
    Running write_stress for 3 seconds: ./write_stress --runtime_sec=3 --low_open_files_mode=true
    Running write_stress for 3 seconds: ./write_stress --runtime_sec=3 --destroy_db=false --delete_obsolete_files_with_fullscan=true
    Running write_stress, will kill after 100 seconds: ./write_stress --runtime_sec=-1 --destroy_db=false --delete_obsolete_files_with_fullscan=true
    write_stress: db/db_impl.cc:2070: void rocksdb::DBImpl::MarkLogsSynced(uint64_t, bool, const rocksdb::Status&): Assertion `log.getting_synced' failed.
    ERROR: write_stress died with exitcode=-6

Reviewers: IslamAbdelRahman, yhchiang, rven, kradhakrishnan, sdong, anthony

Reviewed By: anthony

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D49533

Summary: include/posix/io_posix.h is not a public API. Although include/posix/ is not a public header directory, it is confusing to put non-public headers to under include/. Move it to util/ to be clearer.

Test Plan: Run all tests

Reviewers: rven, IslamAbdelRahman, anthony, kradhakrishnan, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D49611

This reverts commit c37223c0.

Fix MockTable ID storage